The invention relates to computer-logic circuitry, and more particularly programmable logic array (PLA) and read-only memory (ROM) circuitry. Even more particularly, the present invention concerns PLA and ROM circuitry constructed with only diodes and field effect transistors (FETs).
In the development of integrated circuit (IC) technology, a family of at least three types of computer circuitry are needed: random access memories (RAMs), ROMs, and logic circuits. To date, all these types of circuitry have been developed and implemented in IC technology.
Gallium arsenide (GaAs) technology has been of particular interest because of the enhanced speeds active circuit components exhibit compared to those of silicon IC technology. So far, GaAs IC technology has been extensively developed for RAMs and some logic circuits, but not for PLAs or ROMs. The latter lack of development precludes exclusive use of gallium arsenide's advantage in speed in computer and signal processing systems.